“Immobilization of Pyrogallol Red With Gelatin Gel and Appliance the Composite for Total Protein Determination”. Sorbtsionnye I Khromatograficheskie Protsessy, vol. 15, no. 2, Feb. 2018, pp. 223-3, https://doi.org/10.17308/sorpchrom.2015.15/270.